Steam generator



July 2, 1946. F. FALLA 2,402,993

STEAM GENERATOR Filed July 29, 1939 2 Sheets-Sheet l July 2, 1946. F.FALLA 2,402,993

STEAM GENERATOR Filed July 29, 1939 2 Sheets-Sheet 2 l ,o o'

@off/4 iT INVENTOR A TTORN Y Patented July 2, 146

STEAM GENERATOR Fernando Falla, Maplewood, N. J., assigner to FosterWheeler Corporation, New York, N. Y., a corporation of New YorkApplication July 29, 1939, Serial No. 287,291

3 Claims. 1

This invention relates to steam generators and superheaters.

The invention provides a novel arrangement of steam generating and steamsuperheating elements which will produce readily and eliicientlysuperheated steam at various rates of steaming, the arrangement beingsuch that the degree of superheat may be varied as desired throughoutthe load range of the generator.

The invention will be understood from the fole lowing description whenconsidered in connection with the accompanying drawings forming a partthereof, and in which:

Fig 1 is a simplified, vertical sectional View, more or lessdiagrammatic, of a steam generator and superheater embodying theinvention, the section being taken on the line i-I of Fig.. 2, and

Fig. 2 is a horizontal sectional View, taken on the line 2 2 of Fig. 1.

Like characters of reference refer to the same or to similar partsthroughout the several views.

Referring to Figs. l and 2 of the drawings, the generator andsuperheater illustrated includes a setting having a front wall 6, a rearwall 'I, side walls 8 and S, a roof Ii! and a oor II. A steam and waterdrum I2 is disposed in the upper part of the setting at one sidethereof, and a lower or water drum I3 is disposed below and in verticalalignment with the upper drum I2. A vertical bank of steam generatingtubes I4 connects the drums I2 and I3, and a bank or group of tubes I5having their vertically extending portions spaced from the bank of tubesI4, also connect the upper and lower drums.

In the form shown, the space between the enclosing walls of the settingand the bank of tubes I4 is partitioned t0 provide a boiler furnace I5and a superheater furnace I'I. A partition wall I8 of refractory orother suitable material extends normally from front wall 6 to a pointshort of the rear wall l and serves to separate the boiler andsuperheater furnaces. As shown, the tubes I5 are arranged for the mostpart in two vertical rows which extend in a direction parallel to theaxes of the drums I2 and I3, and a partition wall I 9 of refractory orother suitable material extends from the rear wall l between these rowsof tubes to a point short of the front wall E. Another partition wall2i) similar to wall I8, extends from the front wall 6 between the iirsttwo rows of tubes toward the furnace side of the bank I4 to a pointshort of the rear wall 'I.

The boiler furnace IS is fired by one or more fuel burners 2| which arearranged to burn pulverized coal, oil, or gasor any combination of thesefuels. The superheater furnace is indey pendently red by one or moreburners 22, similar to burners 2l. The front and rear walls of theboiler and superheater furnaces are lined with tubes which are connectedinto the boiler circulation. The front walls are lined with tubes 23which extend between upper and lower headers 24 and 25, header 24 beingconnected to the upper drum I2 by suitable connections not shown, whileheader 25 is connected to the lower drum I3 by a plurality ofconnections 2t. Tubes 21,' similarly arranged and connected, line therear wall I of the setting, which constitutes the rear walls of theboiler and superheater furnaces. Tubes 28 line the boiler furnace sideof the partition wall I8, the upper ends of the tubes being connected toa header29 which is connected to upper drum I 2 by tubes 30 which linethe roof of the furnace I6. The lower ends of alternate tubes 28 areconnected to the lower drum I3, while the lower ends of the other tubes28 are connected to a header 3| disposed on the fioor II of the settingat the lower end of side wall 8. The lower ends. or the horizontalportions of the tubes 23 lie below the refractory bottom 32 of the twofurnaces I 5 and Ii. Header 3l is connected to the lower drum byconnections 33 which extend along the oor I I of the setting.

The superheater 34 in furnace I'I is arranged in the form of an invertedU with a partitioned inlet and outlet header 35 and return headers 35and 3l. The header and tube arrangement are -such as to provide aplurality of passes of the vlili steam through the superheater. Thesuperheater tubes line the side walls and roof of the superheaterfurnace I1 from the front wall 6 rearwardly for a distance equal to thelength of the partition wall I8 and thus are shielded from the heatgenerated in the boiler furnace. If desired, the tubes 28 may beomitted, in which eventrthe refractory wall I8 will perform the entireshielding function. Steam is conducted from the steam drum to the inletof the header 35 through line 38 and superheated steam leaves thesuperheater from the outlet end of header 35 through a line not shown.

Water wall tubes l0 line the rear end of side wall 8 between the rearend of the superheater 34 and the rear wall I of the setting. Thesetubes are connected into the boiler circulation by suitable means notshown. The tubes I5 which are disposed between the forward end ofpartition wall I9 and front wall l, are arranged to provide a slagscreen 4I for the gases leaving the furnaces I6.

' flue 43 at the front of the setting. When the superheater furnace l1is fired, the gases or products of combustion produced by the operationof the one or more burners 22, flow through the superheater furnace fromthe front to the rear thereof and pass from the furnace through passage44 between the rear end of partition wall i8 and the rear wall of thesetting. These gases then flow through the boiler furnace I6 from therear portion to the front end thereof, along with the gases produced bythe one or more burners 2| and flow over slag screen 4| through passage42 and over the main bank |4 of boiler tubes and out the flue 43.

The number of burners 2| and burners 22 in operation at any one timewill depend upon the load on the generator and the required temperatureof the steam. Each of the burners 2| and 22 may be controlled in theusual manner to provide for the different "rates or intensitiesl ofring. By varying the number of burners in operation in each furnace, orby varying the intensity of firing of the burners, or both, the desireddegree of superheat at any load` may be obtained.

By the vuse of the refractory partition wall I8, the'superheater and itselements are completely shadowed from the gases in the boiler furnaceIB. By causing the gases from the furnaces I6 and l1 to flow through therelatively narrow gas passage 42 prior to entering the boiler tube bankI4, slag elimination is facilitated, due in part to the cooling effecton the gases by the boiler tubes i4 and I5 lwhich line the Walls of thispassage.

Changes mayv be made in the form, location and arrangement of theseveral parts of the y forms of the invention selected for illustration.Although superheaters are'shown which are heated preponderantly, if notsolely, by radiant heat, the superheaters may be arranged so as to bepartly radiant and partly convection superheaters. In view of thechanges which may be effected in the embodiments selected for disclosurewithout departing from the principles of the invention, it will beunderstood that the invention isV not to be limited excepting by thescope of the appended claims.

What is claimed is: y

1. In a boiler having upper and lower drums interconnected by a bank ofgenerating tubes and means including front and rear walls defining a 4furnace space at one side of said bank; a wall dividing said space toform separate furnace chambers including generating tubes arranged inone or more rows extending across said space from said front wall to apoint short of said rear wall and leaving a passage for gas iiow fromone of said furnace chambers to the other; a superheater in said onechamber having tubes arranged parallel to and closely adjacent thegenerating tubes in said dividing row; individual fuel feeding means forsaid chambers; and other generating tubes arranged in a row on said rearwall opposite the end of said dividing wall and forming one side of saidpassage.

2. Steam generating apparatus comprising a setting having front and rearwalls, a bank of steam generating tubes at one side of the setting,dividing means including tubes connected in circulation with the steamgenerating tubes and dividing the space in the setting at one side ofthe steam generating tubes into a plurality of furnaces including aboiler furnaceA and a superheater furnace, a burner for firing eachfurnace located in the front wall of the setting, said means extendingacross said space from the front wall to a point short cf the rear wallto provide a passage for gas flow from the superheater furnace to aboiler furnace, a superheater having tubes disposed adjacent a walldening the superheater furnace and located substantially out of the pathof the gases flowing through the superheater furnace, other generatingtubes arranged in a row on said rear Wall opposite the end of saiddividing means and forming one side of said passage, and means fordirecting the ow of gases from said furnaces over the steam generatingtubes. Y

3. Steam generating apparatus comprising a setting having front and rearWalls, a group of steam generating tubes at one side of the setting,means including superheater tubes dividing the space Iin the setting atone side of the steam generating tubes into a plurality of furnacesincluding a boiler furnace and a superheater furnace, the superheatertubes being located substantially out of the path of the gases flowingthrough the superheater furnace, a burner for firing each furnacelocated in the front Wall of the setting, said means extending acrosssaid space from the front wall to a point short of the rear wall toprovide a passage for gas iiow from the superheater furnace to a boilerfurnace, superheater tubes on the wall of the superheater furnaceopposite said first-mentioned means and located substantially out of thepath of the gases flowing through the superheater furnace, and means fordirecting the flow of gases from said yfurnaces over the steamgenerating tubes,

FERNANDO FALLA.

